Some prior communication devices when connected to respective ends of a communication path are arranged to test the transmission quality of the path and to exchange signaling information indicative of the results of their respective tests before they exchange data or information. Such prior devices may employ a secondary transmission channel that is either time- or frequency-separated from a primary channel for the exchange of such signaling information. However, in those prior arrangements which do not have secondary-channel capability, only one of the communication devices typically performs the transmission test. The one device typically does this by transmitting a command to establish a loop-back path at the other device and then transmitting one or more predefined code words. The device then compares the code words with the signals that it receives via the loop-back path. If the code words and received signals match, then the one device transmits a command to disconnect the loop-back path and then begins its transmission of data or information. Otherwise, the one device disconnects the loop-back path, as mentioned above, and disconnects itself from the path without notifying (signaling) the other device of its findings. While such arrangements appear to achieve the desired result of testing the communication path and of signaling the results thereof without making use of a secondary channel, they nevertheless consume an inordinate amount of time establishing the loopback path and performing the transmission test.